At present, a number of handheld detectors are available for use in detecting hazardous vapors. These are used by fire fighters, hazmat teams, and others to detect the presence of toxic industrial chemicals, explosive or flammable gases, and chemical warfare agents. Examples of handheld detectors relevant to the present invention include but are not limited to products sold under the trademarks AP4C (Proengin of France), MINIRAE (RAE Systems, Inc.), HGVI and LCD 3.2e (both of Smiths Detection, Inc.).
One limitation of such devices is that an adequate concentration of the analyte or chemical compound to be detected must be available to the sensor element of the detector. This can pose a problem with low volatility hazards, such as certain chemical warfare agents. By way of example, the nerve agent referred to as VX is a sulfonated organophosphorous compound that is highly lethal. VX, however, has a very low vapor pressure in the operational temperature ranges in which it must be detected. For example, at 25 degrees Celsius (° C.), VX has a vapor pressure of only 0.00063 millimeters of Mercury (mm Hg). In comparison, the vapor pressure of water at the same temperature is 23.8 mm Hg, which is roughly 38,000 times that of VX. With such a low vapor pressure, VX is difficult to detect with devices such as the detectors mentioned above. Samples taken for subsequent laboratory analysis suffer from the same problem. Accordingly, what is needed is a low volatility hazard sampling device that when used with the available detection devices or laboratory instruments will provide an accurate and dependable determination of the presence of agent in the sample matrix even when such agent is of the low-volatility type.